During CES in Las Vegas last week a slide showed that the company is preparing a handset with a full 5-inch screen diagonal to take over as its flagship device – likely to be known as the Galaxy S IV.

The Galaxy S III, by comparison, has a screen that’s 4.9 inches in size – and was already considered too big by many when it launched.

But sales have defied expectations, and all manufacturers are lining up to launch big screen phones, which bear more similarities to PDAs of old than they do to – say – the original iPhone a few years ago.

Samsung pioneered these ‘phablets’ – part phone, part tablet – with its Galaxy Note in 2011, and last week manufacturers from HTC, ASUS and Lenovo to lesser known names like ZTE announced supersized phones to compete with Samsung.

The reason is simple, big screen phones may not be very comfortable to make calls on, but many early adopters are finding that once they’ve got one it replaces almost every other portable device they own.

Many analysts are predicting the ‘year of the phablet’ – and with prices for these large screen phones unlikely to be more than a regular smartphone, it’s hard to disagree.

They may not fit in your pocket as easily as a smaller device, but they’re more convenient for most of the tasks that we use our phones for these days – gaming, running apps, browsing the web and reading magazines.

Making actual voice calls is a ridiculously small proportion of the time we spend with our handsets now, and decreasing every year. So there’s every reason to believe that 2013 will be the year of the phablet, and when you next come to upgrade your phone there’s going to be a lot of choices to consider.

The chances are, however, that Samsung will stay ahead of the game. In another announcement, it also showed off its new flexible display technology that allows it to wrap a screen around a phone chassis, so that more of the surface area can be used for pixels.

So it’s likely that the Galaxy S IV will have a bigger display without needing a larger body than the S III. Is it a phone, is it a phablet? It doesn’t really matter – it’s bound to be great.